1. Technical Field
This invention relates to a system and method for detecting incipient collisions, and more particularly to detecting incipient collisions between passenger vehicles and other bodies, objects or passenger vehicles.
2. Discussion of the Related Art
The use of radar to detect the presence and/or speed of objects has become widespread. For example, law enforcement personnel use radar to measure the speed of vehicles, and large vessels such as ships and airplanes use radar to determine their position with respect to other vessels. On a smaller scale, radar is used in automated factories to ensure proper spacing between autonomous roving vehicles.
For passenger vehicles, the use of radar is rather limited. Some systems have been proposed for providing head-on collision avoidance through the use of a full time radar position sensing system. Using such a system, the driver of a trailing vehicle is provided a warning in the event he gets too close to the leading vehicle.
There are several disadvantages with most existing systems. First, with most existing systems, the radar detection apparatus is continuously operating. This does not necessarily pose a problem for vehicle collision detection systems where false warnings are unlikely. However, when attempting to implement a collision detection system for detecting incipient collisions with laterally adjacent vehicles, having the detection system active full time would be undesirable. This is because there are many instances when vehicles travel in the same general line of travel but in parallel paths. In such a situation, issuing a warning whenever a vehicle is next to another vehicle would result in an unacceptable level of false collision warnings. Indeed, such a collision avoidance system should only provide a warning to the vehicle driver when the driver risks selecting a line of travel already occupied by an adjacent vehicle. In those other instances when the driver of the vehicle will not be attempting to change the line of travel into that of an adjacent vehicle's, no warning is required. It would therefore be advantageous to provide for a system and method for detecting incipient collisions between adjacent vehicles traveling in generally parallel lines of travel. Such a system should be capable of discriminating between incipient collisions and non-threatening adjacency.
A second disadvantage of most existing systems is that there is no discrimination between cold-bodied objects, like other cars and garbage cans, and warm-bodied objects, like children and pets. Although any obstacle avoidance system should warn of obstacles regardless of whether they are warm or cold bodied, it can be appreciated that warm-bodied objects should particularly be avoided because a collision with a warm-bodied object will likely be more emotionally upsetting to the driver. Therefore, it would be advantageous if the system and method were capable of distinguishing warm bodies from cold bodies and of modifying the action taken appropriately.
Another disadvantage of most existing systems is that the detection apparatus does not change its range dependent upon speed. For example, when the vehicle is parked or traveling slowly, objects which are very close are of more interest than those far away. Conversely, at high speeds, objects farther away become relevant. It would therefore be advantageous if the detection scheme could modify the range or type of detection used to fit the conditions.
Yet another disadvantage of most known systems is that the warning does not change to match the type of threat detected. For example, an adjacent vehicle traveling along side in the side blind spot would generate the same warning as a child darting out in front of the car. Thus, when the driver hears the warning, he can only be sure that something has been detected somewhere, but he is provided no information as to where or what it is. Therefore, providing warnings which are tailored to the threat posed would be advantageous.